Philodina Rotifer

Philodina belongs to the class Bdelloidea (from the Greek for leech), rotifers that have two ovaries. This type of rotifer moves in two modes. Fully extended it moves like a leech or inchworm along aquatics and detritus. Contracted, with corona extended, it swims freely. To feed, they “cement” themselves to a surface and sway through the water, sifting for smaller organisms or particles of debris. Males have never been observed. Reproduction is solely by parthenogenesis (females producing only females), making rotifers of this class unique in the animal kingdom.